Steel and process of making same



Patented May 22, 1 934:

, 1,959,399 s'rEsL AND PROCESS or MAKING SAME John Thomas Whiteley, Dunellen, N. J., assignor to Isack W. Heyman and S01 L. Zavon, co-

partners trading as Multi Steel 00., New' York,

No Drawing. Application February 25, 1932,

Serial No. 595,220

19 Claims.

The present invention relates to steel and its but it also has a tendency to make it brittle and.

the desire of the steel maker is to produce a steel that i not only very hard but also one that has improved mechanical strength and toughness.

The present invention provides the solution to the problem hereinabove referred to.

covery that a far reaching improvement occurs when certain agents apparently having a catalytic action are added to an. iron melt containing zirconium and titanium. It is the combined use of zirconium and titanium, on the one han and a suitable catalytic agent on the other han that brings about the desired result. The theory that may explain the mechanism of the reaction is as follows:

Zirconium and titanium act as reducing agents i. e. deoxidizing agents on the oxide impurities in the irons Their action is however, incomplete and sluggish. When a suitable catalyst is employed however, an extremely vigorous and complete purifying reaction sets in resulting in a substantially complete union of the oxygen impurities with the zirconium and titanium. I This theory is substantiated by the fact that only enough zirconium and titanium e. g. from 0.2 to 0.5 per cent of each, is necessary, in conjunction with the catalyst, to efiect the desired result. The theory that the zirconium and titanium,

aided by the catalytic agent, exert a purifying action on the low carbon iron is further substantiated by a microscopical examination of the final product produced, as for example, according to Examples 1 or 2 below. The structure is foundto be extremely close grained and homogeneous and tree from inclusions and segregations.

" But whatever the theory may be, 'the fact re.-

'mains that the use ofa trace at certain materials {which for want of a better'name will be termed catalysts) causes some chemical reaction to occur between the zirconium and titanium and the iron melt and this reaction produces steel with a great geimproved hardness and toughness even though carbon content is extremely low, for example,

than0.5 per cent and even as low as 0.05 percent.

The preferred catalyst is a bicromate e; s.

sodium. bichromate but other=strong oxidizing agents may be used for example, potassium bichromate, potassium-chlorate, sodium nitrate,

The invention is in part based upon the disthe steel inthe form of non-volatile metallic and maintains the reaction between the titanium j into a state of activity. Having once attained this .potassium permanganate, sodium perborate, etc.

These examples will suflice to show that any powerful oxidizing agent may be used.

The present invention is not therefore a mere slight improvement in a crowded art, not a narrow portion of a broad field already staked out by prior inventors. So far as known, no one ever suggested or thought of the idea oi using an oxidizing agent to effect .deoxidation and yet that is just what the present invention apparently does. It may be and is believed that the trace of oxidizing agent added activates the zirconium and titanium to exert the full extent of their V deoxidizing powers. Whatever the theory may be, it is'a fact that the trace of oxidizing agent is the key that unlocks the power of the de- T oxidizing agent to confer on the iron melt the remarkable'properties of toughness and hardness possessed by steelmade according to the present invention.

If the .theory herein advanced is the correct one, P then the seemingly paradoxical factexists that the addition of a strong oxidizing agent facilitate I the removal or abstraction of oxygenfrom the melt. This can be explained chemically on the hypothesis that the oxygen impurities exist in oxides which may be reduced by titanium and zirconium, i. e. the titanium and zirconium activatedby the catalyst or strong oxidizing .agent unite with the oxygen of the oxide impurities toiorm oxides of zirconium and titanium. The latter are volatile and pass ofi as smoke or vapor at the high temperature at which the reaction is crawled out. But it is the trace of strong oxidizing agente. g. sodium bichromate which initiates and zirconium on the one hand and theoxide impurities on the other. The trace or small quantity or added oxidizing agent or catalyst acts on the titanium and zirconium and spurs'them activated condition, the zirconium and titanium then proceed to abstract oxygen from the oxide impurities. This theory of the mechanism of the of the reaction is substantiated by the observed fact that although zirconium'and titanium are added to tlie melt, they do not appear in the final 0.30 per cent. It is then brought to a temperature of about 2800 F. .and the following ingredients added in the proportion named.

. Example 1 Per cent Moly 0.40to0.'l5 Chromium 0.10'to 0.30 Silicon 0.20 to 0.50

Manganese 0.50-1701.00

Zirconium (0.50%) 'and titanium (0.20%) are now incorporated and the melt is stirred to thoroughly mix and dissolve the added components.

steel purified by the zirconium-titahium-oxldizing agent reaction to produce a steel having a remarkable combination of hardness and toughness; and to still further increase these properties especially in the direction of toughness, nickel and copper are added. The'preferred proportion of nickel is 0.10 to 0.35 per cent andof copper 0.50 to 0.90 per cent. One of the especially desirable properties of a steel producedas described is that. it requires no tempering to develop its toughness and .hardness and it may be safely- 9 quenched in water-or oil from about 1700 F.- without a subsequent tempering. For example, an

,35. expensive die can be quenched without cracking and is then ready for use without tempering.

I have found that by employing tungsten and vanadium (and also preferably a trace of boron and cobalt) in addition to the elements already- 40 namedin Example 1 above and otherwise proceeding generally as set .forth therein, that the carbon content can be reduced below 0.30 per.

cent andin a typical case illustrating this phase of the invention I proceed'as follows:

A charge of pig iron is purified, as for example by Bessemerizing, until the carbon content is very low, for example 0.10 per cent and to this is added at about 2800 F;

wnezi thorough distribution ofthese metals has occurred, a trace of a powerful oxidizing catalyst e. g., a bichromate ofwhich sodium bichromate is atypical example, is added whereupon a vigorous reaction takes place. when this has subsided, the charge is poured of! and allowed to cool in the form of ingots, etc.

According to this phase of the invention, the

- carbon may beeliminated entirely and in no case is it necessary to exceedapproximately 0.20 per cent. T I

To further aid in developing toughness, I employ copper (0.30 to 7.00 per cent) and-nickel fvigorous reaction between :the zirconium (0.50 to 1,,00 per cent) in combination This application is a continuation in part ofmy copending applications Serial No. 334,856 filed January 24, 1929, and Serial No. 413,136 filed December 10, 1929.

The steel produced according to the present in-. vention is further differentiated from ther steels in that it consists mostly of iron th minimum proportion of whichis of the order of 85 per cent. 7 It does not contain the excessive quantities of expensive elements now commonly used in making alloy steels and the reason why I am enabled to attain a' steel having the properties set forth is to be ascribed'in my opinion to a peculiar crystalline structure created by the potent eifects of the zirconium and titanium in conjunction with the catalytic agent. Therefore, the steel produced according to the present invention is economical toproduce and in steel manufacture, economy is'vital.

Certain very specific percentages of elements have been set forth but it is to be clearly under stood that these are illustrative only and that the invention in its broader aspects is not limited by such specific proportions. Having set forth the principles of the invention and provided certain clear and concise examples of how it may be pra tised, those skilledin the. art will be able to the proportions and make other changes without going beyond the true scope of the invention which is intended to. be defined by the appended claims.

What I claim-is:

1. The method of treating iron which comprises melting it, adding zirconium and titanium and then initiating an exothermic reaction by adding a powerful oxidizing agent selected from the group consistingof sodium bichromate, potassium bichromate, potassium chlorate, sodium nitrat'e', potassium, permanganate and sodiumperborate.

2. The method of purifying iron which comprises melting it, incorporating zirconium and titanium and initiating a vigorous reaction between oxide impurities and said zirconium and titanium by adding a powerful oxidizing agent selectedfrom the group consisting of sodium bichromate, potassium bichromate, potassium chlorate, sodium nitrate, potassium permanga-' nate and sodium perborate.

3. The method of making steel which comprises heating it to a high temperature,.incorporating therewith zirconium and titanium and also molybdenum, manganese, silicon and chromium, and adding a powerful oxidizing'agent selected from the group consistingv of sodium bichromate, potassium bichromate, potassium titanium and oxide impurities. I

4. Themethod of making steel which comchlorate, sodium nitrate, potassium permangaprises heating to a high temperature a batch of iron having not more than 0.5 per cent 'carbon, incorporating therewith zirconium and-titanium and also molybdenum, manganese, siliconandchromium and adding a powerful oxidizing agent selected from the group consisting of sodium titanium and oxide impurities.

5. The method of making steel which com- 1,9593% prises heating, to a high temperature a batch of iron having not more than 0.2 per cent carbon, incorporating therewith zirconium and titanium and also molybdenum, manganese, silicon, chromium, tungsten, vanadium, boron and cobalt, and adding-a powerful oxidizing agent selected from the group consisting of sodium bichromate, potassium bichromate, potassium chlorate, sodium nitrate, potassium permanganate and sodium perborate which initiates a vigorous reaction between the zirconium-and titanium and. oxide impurities.

6. An alloy steel comprising molybdenum 0.40 per cent to 0.75 per cent, chromium 0.10 to 0.30 per cent, silicon 0.20 to. 0.50 per cent, manganese 0.5 to 1.0 per cent and the balance substantially iron, said steel having been treated in the molten condition with zirconium, titanium and sodium bichromate.

' 7. An alloy steel having a. lower carbon content of 0.2 to 0.5 per cent and the balance substantially iron, said steel having been treated in the molten condition with sodium bichromate, zirconium and titanium. I

8. An alloy steel containing carbon 0.2 to 0.5 per cent, molybdenum 0.40 to 0.75 per cent, nickel 0.10 to 0.35 per cent, copper 0.50 to 0.90 per cent, chromium 0.10 to.0.30 per cent, manganese 0.50 to 1.00 per cent and the balance substantially iron and deoxidized by zirconium, titanium and an oxidizing salt selected from the group consisting of sodium bichromate, potassium bichromate, potassium chlorate, sodium nitrate, potassium permanganate and sodium perborate.

9. An .alloy steel containing carbon 0.20 to 0.50 per cent, molybdenum 0.40 to 0.75 per cent, nickel 0.10 to 0.35 per cent, silicon 0.20 to 0.50 per cent, copper 0.50 to 0.90 per cent, chromium 0.10 to 0.30 per cent, manganese 0.50 to 1.00 per cent and the balance substantially iron, said steel having been treated in the molten condition with zirconium, titanium and sodium bichromate.

'10. A deoxidized alloy steel containing 0.2 to 0.5 per cent carbon and the balance substantially iron deoxidized by reaction with zirconium 0.5 to 1.5 per cent, 0.1 to 0.3 per cent titanium and a chromate oxidizing salt.

11. The process of making a hardened and ductile steel comprising treating a quantity of iron with carbon in the proportion of from 0.2 to 0.5 per cent and adding to the melt zirconium, titanium and sodium bichromate at such intervals that they enter into a reaction with one another.

12-. The 'processof making a hardened and due-- tile steel comprising treating a quantity of iron with carbon in the proportion of from 0.2 to 0.5 per cent and adding to the melt zirconium, titanium and a chromate oxidizing agent at such intervals that they enter into a reaction with one another.

13. The process of making steel which comprises treating a quantity of iron with carbon in the proportion of from 0.2 to 0.5 per cent, treating the melt with molybdenum, manganese, silicon and chromium and adding thereto zirconium, titanium and abichromate at such intervals that they enter into a reaction with one another.

14. The process of making a hardened and ductile steel comprising treating a quantity of iron with carbon in the proportion of from 0.2 to 0.5 per cent, treating the melt with molybdenum, nickel, silicon, copper, chromium, manganese and adding thereto zirconium and titanium and a. bichromate oxidizing agent at such intervals that they enter into a reaction with one another.

15-. The process of making a hard tough steel containing carbon in an amount substantially between 0.2 and 0.5 per cent which comprises treating iron at a high temperature with substantially 0.2 to 0.5 per cent carbon, adding zirconium and titanium to deoxidize impurities of the iron and initiating a deoxidizing reaction between the said oxide impurities and the zirconium and titanium by incorporating a trace of a chromate oxidizing agent, whereby the steel is rendered homogeneous..

16. The method of treating iron having a carbon content not greater than 0.5 per cent which comprises melting it with copper 0.3 to 7.0 per cent, nickel 0.1 to 0.35 per cent, molybdenum 0.75

to 1.5 per cent, chromium 0.5 to 1.0 per cent,.

manganese 0.8-to 1.2 per cent, tungsten 0.3 to 0.6 per cent, cobalt a trace, boron a trace, adding zirconium and titanium to the melt and then initiating a combination of the oxide impurities with the zirconium and titanium by the addition of an oxidizing agent selected from the group consisting of sodium bichromate, potassium bichromate, potassium chlorate, sodium nitrate, potassium permanganate and sodiumperborate.

17. The method of treating iron having a carbon content not greater than 0.5 per cent which comprises melting it with copper 0.5 to 0.9 per cent,- nickel 0.1 to 0.35 per cent, molybdenum 0.4 to 0.75 per cent, chromium 0.1 to 0.3 per cent, manganese 0.5 to 1.0 per cent, adding zirconium 0.5 per cent and titanium 0.2 per cent to the melt and initiating a combination of the oxide impurities with the zirconium and titanium by the addition of an oxidizing agent selected from the group consisting of sodium bichromate, potassium bichromate, potassium chlorate, sodium nitrate, potassium permanganate and sodicomprises melting it with copper 0.5 to 0.9 per cent, nickel 0.1 to 0.35 per cent, molybdenum 0.4 to 0.75 per cent, chromium 0.1 to 0.3 per cent, silicon 0.2 to 0.5 percent, manganese 0.5 to 0.1 per cent, adding zirconium in an amount substantially 0.5 per cent and titanium in an amount substantially.0.2 per cent and then initiating a combination of the oxide impurities with the zirconium and titanium by the addition of a trace of an' oxidizing agent selected from the group consisting of sodium bichromate, potassium bichromate, potassium chlorate, sodium nitrate, potassium permanganate and sodium perborate.

19. A method of treating iron having a carbon content not greater than 0.5 per cent which comprises melting it with copper 0.03 to 7 per cent, nickel 0.1 to 0.35 per cent, molybdenum 0.75 to 1.5 per cent, chromium 0.5 to 1.0 per cent, silicon 0.8 to 1.2 per cent, manganese 0.8 to 1.2 per cent, boron a trace, tungsten 0.3 to 0.6 per cent, vanadium 0.1 to 0.2 per cent and cobalt a trace, adding zirconium 0.2 to 0.5 per cent and titanium 0.2 to 0.5 per cent and then initiating a combination of the oxide impurities with the zirconium and titanium by a trace of an oxidizing agent selected from the group consisting of sodium bichromate, potassium bichromate, potassium chlorate, sodium nitrate, potassium permanganate and sodium perborate.

JOHN THOMAS WHITELEY. 5o 

